A well generally includes a wellbore (or “borehole”) that is drilled into the earth to provide access to a subsurface formation (a geographic formation below the earth's surface) to facilitate the extraction of natural resources, such as hydrocarbons and water from the subsurface formation, to facilitate the injection of fluids into the subsurface formation, or to facilitate the evaluation and monitoring of the subsurface formation. In the petroleum industry, wells are often drilled to extract (or “produce”) hydrocarbons, such as oil and gas, from subsurface formations. The term “oil well” is used to refer to a well designed to produce oil. In the case of an oil well, some natural gas is typically produced along with oil. A well producing both oil and natural gas is sometimes referred to as an “oil and gas well” or “oil well.”
Creating an oil well typically involves several stages, including a drilling stage, a completion stage and a production stage. The drilling stage normally involves drilling a wellbore into a subsurface formation that is expected to contain a concentration of hydrocarbons that can be produced. The portion of the subsurface formation expected to contain hydrocarbons is often referred to as a “hydrocarbon reservoir” or “reservoir.” The drilling process is usually facilitated by a drilling rig that sits at the earth's surface. The drilling rig provides for operating a drill bit to cut the wellbore, hoisting, lowering and turning drill pipe and tools, circulating drilling fluids in the wellbore, and generally controlling various operations in the wellbore (often referred to as “down-hole” operations). The completion stage involves making the well ready to produce hydrocarbons. In some instances, the completion stage includes installing casing pipe into the wellbore, cementing the casing in place, perforating the casing pipe and cement, installing production tubing, installing downhole valves for regulating production flow, and pumping fluids into the well to fracture, clean or otherwise prepare the reservoir and well to produce hydrocarbons. The production stage involves producing hydrocarbons from the reservoir by way of the well. During the production stage, the drilling rig is normally removed and replaced with a collection of valves at the surface, often referred to as a “production tree”. The surface valves are operated in coordination with downhole valves to regulate pressure in the wellbore, control production flow from the wellbore and provides access to the wellbore in the event further completion work is needed. A pump jack or other mechanism can provide lift that assists in extracting hydrocarbons from the reservoir, especially in instances where the pressure in the well is so low that the hydrocarbons do not flow freely to the surface. Flow from an outlet valve of the production tree is normally connected to a distribution network of midstream facilities, such as tanks, pipelines and transport vehicles that transport the production to downstream facilities, such as refineries and export terminals.
Often times the downhole valves include inflow control valves (ICVs) installed in the wellbore to regulate the flow of substances in the wellbore. In particular, ICVs can be installed in the wellbore to regulate the flow of substances, such as oil, gas and water, between the subsurface formation and a production conduit, such as casing or production tubing that provides a flow path to the surface. In the case of a well being operated as a production well, for example, a completion unit may include one or more ICVs that regulate the inflow of production fluids from a reservoir, into a central passage of the casing or production tubing that directs the production fluids to the surface for collection.
The operational state of an ICV is typically controlled remotely, for example, by a well control system at the surface. ICVs can be controlled to actuate between a fully opened position and fully closed position. The fully opened position includes opening the entire flow area of the valve to facilitate the flow of substances, such as production fluids, across the ICV. The fully closed position closes the entire flow area of the valve to block the flow of substances across the ICV. Normally, an ICV has several partially opened positions that can be utilized to regulate flow through the ICV. For example, an ICV may have ten “steps”, with step 0 being a 0% open position (referred to as a “fully closed” position), step 1 being a 10% open position, step 2 being a 20% open position, and so forth, with step 10 being a 100% open position (referred to as a “fully opened” position). The state of an ICV may be dictated by a variety of factors, such as desired flow rate and pressure, water cut (volume of produced water with respect to total fluid production), and flow contribution of other portions of the well.